Tanks used in solar installations are illustrated in U.S. Pat. Nos. 4,027,821 and 4,044,754. In a drain-down or fully drainable solar energy collector system, it is important for good operation and efficiency to use a tank having a coil type heat exchanger to receive the solar heated water and to exchange that heat to a second fluid, such as domestic hot water, circulated through the coil heat exchanger.
In the construction of a tank of this type, the heat exchanger coil needs support against movement during shipment. Heretofore, the coils of the heat exchanger have been supported at the inlet/outlet fittings along the tank wall. Such mounting permits some movement of the coil in the tank. Heat exchanger coils of the type contemplated are usually provided with transverse, thin metallic fins which have sharp corners and are utilized to extend the area of the thermal transfer surface. Excessive movement of the coil within the tank may cause damage to the fragile glass lining of the tank or the fins of the tubing. Also, the tubing may become distorted or fractured resulting in either a restricted fluid flow through the coil in use or a failure. Since the coil is sealed within the tank, a failure of operation of the heat exchanger causes downtime of the system for repair or replacement of the tank.